Sleeko,
Did you get the bridge from eBay in the above link? That appears to be a leftover Park Ave X-180 bridge from Corona. The New Hartforrd GSR archtops all appear to be sporting the 2 footed bridge base with TOMs. Newark Street are also 2 footed with a mix of TOM and compensated rosewood as shown on your Corona X-150. My 2000 Westerly X-150D has the float rosewood base with the compensated saddle as shown in your pic above. I'd be interested to know how the straight line (but angled) saddle on the one from eBay works out. It appears that is what was shipped on the X180 Park Ave from Corona. Not sure if anything else went out the door that way. Maybe some of those fancy Benedetto (I mean that respectfully) that shipped out of Corona had them too.
BTW, your X150 is simply stunning.